Residual strain in deuterated Ti thin films (original) (raw)
Interdependence between stress and texture in arc evaporated Ti–Al–N thin films
Surface and Coatings Technology, 2007
Ex-situ X-ray diffraction was used to characterize the stress state and texture of TiAlN monolayer and TiN/TiAlN multilayer hard coatings deposited on WC-Co and tool steel substrates using the cathode arc evaporation method. For all coatings the compressive residual stress was found to be higher in the film deposited on tool steel than that deposited on WC-Co; this is due to the difference in the linear thermal expansion coefficient of the two substrates. X-ray diffraction polar scan measurements showed that the preferred orientation of the crystallites exhibits cylindrical symmetry but it is inclined with respect to the sample surface. Moreover, the inclination angle of the (002) diffracting planes increases with the increase of the residual stress in the coating. Different mechanisms that could explain the interdependence between fiber texture and residual stress are discussed.
Nucleation and growth microstructural study of ti films on 304 SS substrates
Materials Research, 2004
Coating of steel surfaces with titanium films has been studied with the objective to protect them against corrosion, and to create an intermediate film for CVD diamond and TiN film deposition. In this work, the nucleation, growth mechanisms and microstructural formation of the titanium films deposited on 304 stainless steel (304 SS) substrate are presented and discussed. The titanium films of variable thickness were obtained by vapour phase deposition produced by electron beam. The surfaces of these samples were observed by scanning electron microscopy. The cross sections of these samples were observed by using an atomic force microscope. The Ti film-304 SS interfaces were analyzed by X-ray diffraction. The results showed that titanium films have a columnar growth. The Ti film-304 SS interface had a residual compression stress at room temperature due to the interdiffusion process.
Thin Solid Films, 1998
. The microstructure of a series of Ti Al N films prepared by Chemical Vapour Deposition CVD is investigated using Scanning 1yx x Ž . Ž . Ž . Electron Microscopy SEM , Transmission Electron Microscopy TEM and Electron Energy Loss Spectroscopy imaging EELS . A comparison is made with the microstructure of a film obtained using a magnetron sputtering method. CVD films were prepared with substrate temperatures ranging from 400 to 4508C. Plan-view and cross-sectional observations show that they are made of nanocrystallites, a majority of these being organised in columnar clusters. The sharpest electron diffraction patterns obtained from the films are indexed in terms of the fcc TiN structure-type with a lattice parameter a, decreasing slightly with increasing aluminum content. In the film deposited by magnetron sputtering the main structure is fcc TiN-type with a lattice parameter of 4.17 A and the observed grain size is 300 nm, a value much larger than the grain size obtained from CVD films, although the deposition was done at room temperature. The EELS imaging technique also shows that throughout the series, Ti, Al and N are homogeneously distributed. q 1998 Elsevier Science S.A.
Acta Materialia, 2002
We report the stress relaxation behavior of arc-evaporated TiC x N 1Ϫx thin films during isothermal annealing between 350 and 900°C. Films with x ϭ 0, 0.15, and 0.45, each having an initial compressive intrinsic stress s int ϭ Ϫ 5.4GPa, were deposited by varying the substrate bias V s and the gas composition. Annealing above the deposition temperature leads to a steep decrease in the magnitude of s int to a saturation stress value, which is a function of the annealing temperature. The corresponding apparent activation energies for stress relaxation are E a ϭ 2.4, 2.9, and 3.1eV, for x ϭ 0, 0.15, and 0.45, respectively. TiC 0.45 N 0.55 films with a lower initial stress s int ϭ Ϫ 3GPa, obtained using a high substrate bias, show a higher activation energy E a ϭ 4.2eV. In all the films, stress relaxation is accompanied by a decrease in defect density indicated by the decreased width of X-ray diffraction peaks and decreased strain contrast in transmission electron micrographs. Correlation of these results with film hardness and microstructure measurements indicates that the stress relaxation is a result of point-defect annihilation taking place both during shortlived metal-ion surface collision cascades during deposition, and during post-deposition annealing by thermally activated processes. The difference in E a for the films of the same composition deposited at different V s suggests the existence of different types of point-defect configurations and recombination mechanisms.
Microstructure, Stress and Texture in Sputter Deposited TiN Thin Films: Effect of Substrate Bias
Advanced Materials Research, 2014
Titanium nitride thin films deposited by reactive dc magnetron sputtering under various substrate bias voltages have been investigated by X-ray diffraction. TiN thin films exhibits lattice parameter anisotropy for all bias voltages. Preferential entrapment of argon atoms in TiN lattice has been identified as the major cause of lattice parameter anisotropy. Bombardment of argon ions during film growth has produced stacking faults on {111} planes of TiN crystal. Stacking fault probability increases with increasing substrate bias voltages. X-ray diffraction line profile analysis indicates strain anisotropy in TiN thin films. Diffraction stress analysis by d-sin2ψ method reveals pronounced curvature in the plot of inter-planar spacing (d) (or corresponding lattice parameter (a)) versus sin2ψ. Direction dependent elastic grain interaction has been considered as possible source of the observed anisotropic line broadening.
X-ray diffraction on nanocrystalline Ti1−xAlxN thin films
Journal of Alloys and Compounds, 2004
Microstructure of titanium aluminium nitride thin films deposited using arc evaporation was investigated for different aluminium contents. From Ti 0.96 Al 0.04 N to Ti 0.38 Al 0.62 N, the dominant phase in the coatings was the fcc Ti 1−x Al x N. In this concentration range, the compressive residual stress as well as the hardness of the coatings increased with increasing aluminium contents. Crystallites of Ti 1−x Al x N were strongly textured; the preferred orientation was found to be related to the deposition geometry, not to the composition of the coatings. Concurrently, preferred orientation of crystallites was found to be a very important parameter influencing the crystal anisotropy of lattice deformation and the coherence of neighbouring crystallites. At higher aluminium contents (x > 0.8), the dominant phase was the hexagonal AlN; the hardness of the films decreased. (D. Rafaja). structure: scatter of lattice parameters, very high residual stress and very high microstrain. 0925-8388/$ -see front matter
Morphological study of magnetron sputtered Ti thin films on silicon substrate
2008
Titanium films on Si(1 0 0) substrate were deposited by DC-magnetron sputtering. The effect of substrate temperature on the microstructural morphologies of the films was characterized by using field emissionbased scanning electron microscopy/electron back scattered difffraction (FE-SEM/EBSD) and atomic force microscopy (AFM). X-ray diffraction was used to characterize the phases and crystallite size of the Ti films and it was observed that according to the first figure of this article: (0 0 2) orientation increases from 200 • C and it changes into (1 0 1) orientation from 300 • C. The SEM analysis of the Ti films, deposited in Ar atmosphere, showed two-and three-dimensional hexagonal structure of the grains at the substrate temperature of 200 • C and >200 • C, respectively. The increase in grain size of Ti films with the substrate temperature was confirmed by EBSD and AFM characterization. The average surface roughness of the Ti films has increased with increase in substrate temperature as evident from the AFM study.
In situ study of Ni–Ti thin film growth on a TiN intermediate layer by X-ray diffraction
Sensors and Actuators B-chemical, 2007
Shape Memory Alloy (SMA) Ni-Ti thin films have attracted much interest as functional and smart materials due to their unique properties. However, there are still important issues unresolved like formation of film texture and its control as well as substrate effects. In this study, nearequiatomic films were obtained by co-sputtering from Ni-Ti and Ti targets in a process chamber installed at a synchrotron radiation beamline. In-situ X-ray diffraction during the growth of these films allowed establishing a relationship between structure and deposition parameters. The effect of a TiN layer deposited on top of the SiO 2 /Si(1 0 0) substrate prior to the deposition of the Ni-Ti films was analysed. These experiments show that TiN acts not only as a diffusion barrier, but also induces different crystallographic orientations. A TiN layer with ≈215 nm thickness induces the preferential growth of (1 1 0) planes of the Ni-Ti B2 phase parallel to the substrate from the beginning of the deposition with a constant growth rate during the whole deposition. For a TiN thickness of ≈15 nm, the diffraction peak B2(1 1 0) also appears from the beginning of the deposition but much less intense. In this latter case, the B2(2 1 1) peak was also detected having observed a crossover from 1 1 0 oriented grains dominating at small thicknesses, to 2 1 1 oriented grains taking over at larger thicknesses. The same orientations and similar intensities were observed for a Ni-Ti film deposited on a TiN layer with ≈80 nm.
Structural and nano-mechanical characterization of TiN / Ti1−xAlxN multilayered thin films
International Conference on Nanoscience, Engineering and Technology (ICONSET 2011), 2011
Nb thin films were deposited onto Si wafers by direct current (DC) magnetron sputtering at different deposition pressures. The microstructure and nanomechanical properties of Nb films were investigated by scanning electron microscope, X-ray diffractometer, transmission electron microscope, atomic force microscope and nanoindenter. The results revealed that the grain size, thickness, surface roughness, the reduced elastic modulus (Er) and hardness (H) values of Nb thin films increased at the pressure range of 0.61-0.68 Pa. Meanwhile, the porosity of Nb films decreased with the increase in deposition pressure. The lattice deformation of Nb thin films changed from negative to positive with the increase in deposition pressure. It is concluded that deposition pressure influences the microstructure and nanomechanical properties of Nb films.